This invention relates to fluidised bed combustion apparatus and to furnaces and incinerators embodying such equipment. The invention is particularly concerned with the feed of material to be burnt in the fluidised bed, such material being either waste material or low grade fuel to be burnt with the object either of disposal or the generation of heat for a useful purpose.
It has been proposed to provide a fluidised bed combustion apparatus in which a fluidised bed of granular material is supported in a housing or combustion chamber on an air diffuser bed support. In such an arrangement fuel or waste material to be burnt either to raise heat or for disposal purposes is fed into the fluidised bed to be burnt therein. The oxygen for combustion comes at least in part and usually entirely from air fed into the bed from the diffuser support to fluidise the bed. The bed is usually formed of granular material such as sand or other refractory material and may comprise in part ash residue from previous combustion.
The diffuser is in some cases arranged to slope from one side of the bed to the other and the supply of fluidising air to the various areas of the diffuser is selectively controlled to cause the bed materials to circulate about a generally horizontal axis extending across the slope of the diffuser.
It is an object of the present invention to provide an arrangement for feeding material to be burnt into a fluidised bed, particularly a fluidised bed which is arranged to circulate in the manner described above about a generally horizontal axis.